In recent years, in OA instruments and electronic parts (in particular, mobile instruments) such as personal computers, printers, cellular telephones, PDA, digital cameras, and digital video cameras, their productions increase with their diffusion, and size reduction and thinning are being designed in parallel to realization of high function. For example, in cellular telephones which are a representative instrument of mobile instruments, for the sake of enlarging the display screen and improving portableness, the major parts to be constructed tend to become thin. In general, a display portion is mainly composed of an LCD module and a backlight unit, and a variety of parts in the sheet form are frequently used (laminated) for the purpose of revealing functions such as light emission, reflection, light shielding, and light guiding. In the fabrication (junction) of these parts, double-sided pressure-sensitive adhesive tapes or sheets, screws, adhesives, and the like are usually used (see JP-A-2002-249741) (The term “JP-A” as used herein means an “unexamined published Japanese patent application”).
In the fabrication (junction) of parts, for example, in the case where a double-sided pressure-sensitive adhesive tape or sheet is used, because of restrictions in the thickness of products or parts, double-sided pressure-sensitive adhesive tapes or sheets having a relatively thin thickness tend to be used among commercially available double-sided pressure-sensitive adhesive tapes or sheets. However, in many cases, double-sided pressure-sensitive adhesive tapes or sheets merely composed of a pressure-sensitive adhesive layer only (so-called “substrate-less double-sided pressure-sensitive adhesive tapes or sheets”) are used as conventional double-sided pressure-sensitive adhesive tapes or sheets having a thin thickness. As the thickness is decreased, the strength of a double-sided pressure-sensitive adhesive tape or sheet is lowered so that the double-sided pressure-sensitive adhesive tape or sheet is cut during the adhesion works, or it is actually difficult to again release a double-sided pressure-sensitive adhesive tape or sheet which has been stuck once, resulting in a lowering of the workability.
On the other hand, in sites where a further ultra-thin layer structure is required, conventional double-sided pressure-sensitive adhesive tapes or sheets become difficult for use because of restrictions in the clearance. For this reason, the object is achieved by coating a liquid adhesive in place of the double-sided pressure-sensitive adhesive tape or sheet.
However, since an adhesive is liquid with respect to its properties, it is difficult to make the coating thickness uniform. Also, since its fluidity is high, an inconvenience following the adhesion into other portions than the necessary site is liable to occur. Further, in general, it takes a time to complete curing, an aspect of which becomes a factor of lowering the productivity of fabrication works, and therefore, such is inferior in economy.